| Registro completo |
| Provedor de dados: |
ArchiMer
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| País: |
France
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| Título: |
δ13C decreases in the upper western South Atlantic during Heinrich Stadials 3 and 2
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| Autores: |
Campos, Marilia C.
Chiessi, Cristiano M.
Voigt, Ines
Piola, Alberto R.
Kuhnert, Henning
Mulitza, Stefan
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| Data: |
2017-04
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| Ano: |
2017
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| Resumo: |
Abrupt millennial-scale climate change events of the last deglaciation (i.e. Heinrich Stadial 1 and the Younger Dryas) were accompanied by marked increases in atmospheric CO2 (CO2atm) and decreases in its stable carbon isotopic ratios (delta C-13), i.e. delta(CO2atm)-C-13, presumably due to out-gassing from the ocean. However, information on the preceding Heinrich Stadials during the last glacial period is scarce. Here we present delta C-13 records from two species of planktonic foraminifera from the western South Atlantic that reveal major decreases (up to 1%) during Heinrich Stadials 3 and 2. These delta C-13 decreases are most likely related to millennial-scale periods of weakening of the Atlantic meridional overturning circulation and the consequent increase (decrease) in CO2atm (delta(CO2atm)-C-13). We hypothesise two mechanisms that could account for the decreases observed in our records, namely strengthening of Southern Ocean deep-water ventilation and weakening of the biological pump. Additionally, we suggest that air-sea gas exchange could have contributed to the observed delta C-13 decreases. Together with other lines of evidence, our data are consistent with the hypothesis that the CO2 added to the atmosphere during abrupt millennial-scale climate change events of the last glacial period also originated in the ocean and reached the atmosphere by outgassing. The temporal evolution of delta C-13 during Heinrich Stadials 3 and 2 in our records is characterized by two relative minima separated by a relative maximum. This "w structure" is also found in North Atlantic and South American records, further suggesting that such a structure is a pervasive feature of Heinrich Stadial 2 and, possibly, also Heinrich Stadial 3.
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| Tipo: |
Text
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| Idioma: |
Inglês
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| Identificador: |
https://archimer.ifremer.fr/doc/00420/53162/55294.pdf
https://archimer.ifremer.fr/doc/00420/53162/55295.pdf
DOI:10.5194/cp-13-345-2017
https://archimer.ifremer.fr/doc/00420/53162/
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| Editor: |
Copernicus Gesellschaft Mbh
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| Formato: |
application/pdf
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| Fonte: |
Climate Of The Past (1814-9324) (Copernicus Gesellschaft Mbh), 2017-04 , Vol. 13 , N. 4 , P. 345-358
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| Direitos: |
Author(s) 2017. This work is distributed under the Creative Commons Attribution 3.0 License.
info:eu-repo/semantics/openAccess
restricted use
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